The death of Kim Jong-Il throws into disarray a US policy of waiting patiently for change in nuclear-armed North Korea, with officials nervously seeking clues on the regime’s future direction.

...the US now must deal with an untested young leader who remains a mystery on the global stage

After years of on-off efforts to end North Korea’s nuclear programme, the US recently made a tactical shift to maintain low-level dialogue as a way to discourage future provocations even if no big issues are resolved.

But experts said that Kim Jong-Il’s death fundamentally changes US calculations. Instead of a recalcitrant strongman, the US now must deal with an untested young leader who remains a mystery on the global stage.

Kim Jong-Il, 69, had been groomed for 14 years as successor to his father, the regime’s founder Kim Il-Sung. Heir apparent Kim Jong-Un is in his late 20s and is believed to lack a firm support base within the opaque regime.

North Korea expert L. Gordon Flake, executive director of the Mansfield Foundation, said that US diplomacy is dependent on policy, not personalities, but that Pyongyang is unlikely to be able to make key decisions right now.

But Mr Flake, who advised then-senator Barack Obama during his Presidential campaign, said the longer-term implications could be different. Kim Jong-Il set off repeated crises since inheriting power in 1994, including carrying out two tests of nuclear weapons.

“In the short run, there is the risk that North Korea may lash out. But in the long run, I don’t think there’s any way to bemoan Kim Jong-Il’s passing,” he said.

US policymakers had hinted in recent weeks that they were making some headway with North Korea, which could perhaps open the way for more formal talks or a resumption of US food assistance to the impoverished state.

Mr Obama’s Administration had been adamant that it will not resume formal negotiations until North Korea clearly commits to past agreements on denuclearisation.

In a presentation last year, a military strategist warned that the US needed to study all possible outcomes as a complete collapse of the nuclear-armed regime could trigger a crisis unseen since World War II.

Colonel David Maxwell of the Army’s Special Operations Command, said that N. Koreans should be expected to resist fiercely any foreign forces and could mount an insurgency far more sophisticated than those seen in Iraq or Afghanistan.